The alternating direction method of multipliers (ADMM) is widely used in solving structured convex optimization problems due to its superior practical performance. On the theoretical side however, a counterexample was shown in [7] indicating that the multi-block ADMM for minimizing the sum of N (N ≥ 3) convex functions with N block variables linked by linear constraints may diverge. It is therefore of great interest to investigate further sufficient conditions on the input side which can… CONTINUE READING